patrick@rothera:~$ apt-cache search linux-headers
linux-headers-2.6.15-23 - Header files related to Linux kernel version 2.6.15
linux-headers-2.6.15-23-386 - Linux kernel headers 2.6.15 on 386
linux-headers-2.6.15-23-686 - Linux kernel headers 2.6.15 on PPro/Celeron/PII/PIII/PIV SMP/UP
linux-headers-2.6.15-23-k7 - Linux kernel headers 2.6.15 on AMD K7 SMP/UP
linux-headers-2.6.15-23-server - Linux kernel headers 2.6.15 on Server Equipment
linux-headers-2.6.15-23-server-bigiron - Linux kernel headers 2.6.15 on BigIron Server Equipment
linux-headers-2.6.15-25 - Header files related to Linux kernel version 2.6.15
linux-headers-2.6.15-25-386 - Linux kernel headers 2.6.15 on 386
linux-headers-2.6.15-25-686 - Linux kernel headers 2.6.15 on PPro/Celeron/PII/PIII/PIV SMP/UP
linux-headers-2.6.15-25-k7 - Linux kernel headers 2.6.15 on AMD K7 SMP/UP
linux-headers-2.6.15-25-server - Linux kernel headers 2.6.15 on Server Equipment
linux-headers-2.6.15-25-server-bigiron - Linux kernel headers 2.6.15 on BigIron Server Equipment
linux-headers-386 - Linux kernel headers on 386
linux-headers-686 - Linux kernel headers on PPro/Celeron/PII/PIII/PIV
linux-headers-k7 - Linux kernel headers on AMD K7
linux-headers-server - Linux kernel headers on Server Equipment.
linux-headers-server-bigiron - Linux kernel headers on BigIron Server Equipment.
linux-source-2.6.15 - Linux kernel source for version 2.6.15 with Ubuntu patches
patrick@rothera:~$